Brake



March 7, 1933. R, KQHR 1,899,967

BRAKE Original Filed June 23, 1927 Fatented Mar. 7, i933 ST'E'E ROBERTF. KOHlPt, OF SOUTH BEND,

INDIANA, ASSIGNOR TO THE STUDEBAKER CORTO- RATIOIN', OF SOUTH BEND,INDIANA, A CORPORATION OF NEW JERSEY original application filed June 23,1927, Serial No. 200,944. Divided and this application filed May 3,

1929. Serial-Ho. 360,123.

This invention relates to vehicle brakes and particularly to theoperating mechanism therefor and is a division of my copendingapplication, Serial No. 200,944 filed June 23, 192

The principal object of the resent invention is to pr'ovide a vehiclebra c with an operating mechanism which will engage the brake with thebrake drum as effectively when the drum is rotating in a clockwisedirection as when it is rotating in a counter-clockwise direction.

Another object is to provide a vehicle brake with a brake operatingmechanism which will expand the brake into engagement with the brakedrum in a direction circumferentially of the drum.

Another object is to provide a vehicle brake with an operating mechanismwhich engages the brake element substantially in the circular paththereoffor expanding the brake element in a circumferential directioninto engagement with the rotating brake drum.

Another object is to provide a vehicle brake with operating meanscomprising a pair of pivoted levers and a free floating cylinderengaging both levers for moving the same to expand the brake elementinto friction en gagement with the brake drum.

A further object is to provide a vehicle brake with an operatingmechanism comprising a pair of pivotal levers engaging the ends of thebrake element substantially in the circular path thereof, a freefloating cylinder engageable with both levers, and an cecentric'formoving the cylinder radially outwardly to pivot the levers to expand thebrake element into frictional engagement with the brake drum.

A further object is to provide a vehicle brake with an operatingmechanism comprising a pair of pivoted levers engaging the ends of thebrake element substantially in the circular path thereof, a freefloating cylinder engageable with both levers, and an eccentric formoving the cylinder radially outwardly to pivot the levers to expand theband in a circumferential direction into frictional engagement with thebrake drum.

These being among the objects of the prescoil springs ent invention, thesame consists of certain features of construction and combination ofparts to be hereinafter described with reference to the accom anyingdrawing, and then claimed, having t e above and other objects in view.

In the drawing which illustrates a suitable embodiment of the presentinvention,

Figure 1 is a vertical transverse section taken through the left frontwheel of a motor vehicle showing the brake operating mechanism.

Figure 2 is a fragmentary sectional view taken on the line 2-2 of Figure1,-more clearly showing the brake expanding mechanism.

Figure 3 is a perspective view of a portion of the dust cover and thestop member mounted thereon.

Figure 4 is a perspective view of the lever operating cylinder.

Figure 5 is a perspective view of the cam for operating the cylinder.

Referrin to the accompanying drawing in which like numerals refer tolike parts throughout the several views, a conventional steering knuckle15 having a stub axle 16 formed thereon is pivoted to a front axle 17.Mounted on the stub axle 16 is a bearing 18 which supports the rotatablewheel hub 19 on which the vehicle wheel 20 and the brake drum 21 areconcentrically arranged and secured. A brake drum dust cover 22 issecured to the steering knuckle 15 adjacent to the brake drum 21 toprovide a support for the brake mechanism.

As shown in Figure 2, a thin section steel brake band 23 faced with asuitable friction material 24 is concentrically arranged within thebrake drum 21 and is normally held in spaced relationship therefrom by apair of 25 which tend to draw the ends of the same inwardly toward eachother. The ends of the springs 25 are hooked through the dependingportions of Z-shaped brackets 27 secured to the extreme ends of the band23.

The coil springs 25 as just mentioned contract the band 23 and draw theends of the same toward each other until the ends 28 of. the Z-shapedbrackets 27 abut against the operating levers to be hereinafterdescribed positioned within the side walls of a [Ll-shaped stop member29 secured to the dust cover 22 by the rivets 30,

Suitably secured to the outer side of the dust cover 22 is a support 31having an inwardly extending tubular portion 32 adapted to rotatablyreceive an operating shaft 33 having a cam 34 thereon as is clearlyshown in perspective in Figure 5. The shaft 33 has a lever 35 secured atits outer end which has a brake rod 36 pivoted thereto and connectedwith some source of braking pressure such as a conventional brake pedal,not shown.

A support 37 secured to the dust cover 22 has mounted thereon two pins38. The pins 38 support two pivoted levers 39 having inclined faces 40and lips 41 which engage the ends 28 of the Z-shaped brackets 27directly in the circular path of the band 23. A plate 12 which isretained on the pins 38-by nuts 43 holds the levers 39 against thesupport 37 to prevent transverse movement of the same. A cylindricalroller dd is positioned between the support 37 and the plate 42 and isguided therebetween when it is moved radially outwardly by the rotatablecam 34 to contact with the inclined faces 40 of the levers 39.

In normal inoperative position as shown in Figure 2 the levers 39contactwith each other to act as stops for the end of the band 23 but inoperative position as shown in dash and dotted outline in Figure 2, oneend oi? the band 23, depending upon the direction of rotation of thedrum 21, is held against rotation by the U-shaped stop 29 interposedbetween the ends of the band 23.

Movement of the cylinder 44! against the inclined faces 40 of the levers39 forces the levers 39 to rotate in opposite directions about theirpivot pins 38 against the tension of the springs 25 and expands the band23 into engagement with the drum 21.

At the instant the friction facing 24: engages the drum 21 the band 23rotates with the drum 21 until the right hand end of the band (when thebrake drum is rotating in a counter-clockwise direction) abuts againstthe right side of the stop 29. This causes both levers 39 to rotate in acounter-clockwise direction and further radial movement of the cam 34:causes the cylinder 44: to pivot the left lever 39 and rotate the samein a counter-clockwise direction to expand the band 23 in acircumferential direction into further frictional engagement with thedrum 21 to retard the rotation thereof, the right lever 39 being heldagainst rotation on movement of the cylinder at by the resistance of theright hand end of the band 23 to expand in a clockwise direction. Thebrake mechanism works in the same manner when the brake drum 21 isrotating in a clockwise directionwith the exception that the left handend of the band 23 engages with the left side of the stop 29 and theright end nseaeev of the band 23 is moved for expansion. lit can be seenthat the band 23 will be expanded into engagement with the drum 21 in acircumferential direction because each of the levers 39 contacts withthe ends 28 of the Z-shaped brackets 27 on lines approximately in thecircular path of the band 23.

It will thus be seen that the maximum efdciency of an" internalexpanding band brake is obtained in the present invention by expandingthe band in a circumferential direction by exerting pressure against theends of the same substantially in the circular path thereof.

It is to be understood that the present invention is not limited to theparticular shapes of the operating levers shown or other details ofconstruction but that formal changes may be made in the specificembodiment of the invention described without departing from the spiritand substance of the broad invention the scope of which is commensuratewith the appended claims.

What ll claim is:

1. lln a-brake mechanism, a rotatable drum, braking means movable toengage said drum, an actuating means therefor comprising a pair ofpivoted levers engaging the ends of said braking means substantially inthe circular path thereof, a free floating cylinder positioned betweensaid levers and contacting therewith, and a rotatable cam for movingsaid cylinder outwardly to pivot one or both of said levers for engagingsaid braking means with said drum.

2. ln a brake mechanism, a rotatable drum, braking means movable toengage said drum, a pair of levers having inclined faces intermediatetheir ends engageable with said braking means, and a free floatingcylinder enga 'ng said inclined faces for actuating one or oth of saidlevers to move said braking means into engagement with said drum.

3. In a brake mechanism, a rotatable drum, braking means movable toengage said drum, a pair of levers engageable with said braking means,stops on said levers cooperating to limit the contraction of saidbraking means, and free floating means engaging said levers foractuating one or both of said levers to move said braking means intoengagement with said drum.

1. In a brake mechanism, a rotatable drum, braking means movable toengage said drum, a pair of levers engageable with said braking means,said levers normally engaging each other to limit the contraction ofsaid braking means, and free floating means engaging said levers foractuating one or both of said levers to move said braking means intoengagement with said drum.

5. ln a brake mechanism, arotatable drum,

braking means movable to engage said drum,

a pair of levers engageable with said braking means, said levers havinginclined faces terlOti minating in stops whereby said levers normallyengage each other to limit the contraction of said braking means, and afree floating cylinder engaging said inclined faces for actuating one orboth of said levers to move said braking means into engagement with saiddrum.

6. In a brake mechanism, a rotatable drum,

brakin means movable to engage said drum,

pivote levers engaging said braking means and normally engaging eachother, a free floating member engaging said levers and a rotatable camfor moving said free floating member to move said levers out ofengagement with each other and to engage said braking means with saiddrum.

7 In a brake mechanism, a rotatable drum, braking means engageabletherewith, pivoted levers engaging said braking means and normally engang each other, and means movable radial y of said drum for moving saidlevers out of engagement with each other and to engage said brakingmeans with said drum.

8. In a brake mechanism, a rotatable drum, braking means engageabletherewith, levers provided with spaced pivots engaging said brakingmeans, at least one of said levers having an inclined face, and freefloating means movable radially of said drum and guided solely by saidlevers for moving one or both of said levers to engage said raking meanswith said drum.

9. In a brake mechanism,'a rotatable drum braking means engageabletherewith, and pivoted levers engageable with said braking means formoving the same into engagement with said drum, said levers cooperatingto provide a stop for said braking means to limit the contractionthereof.

10. In a brake mechanism, a rotatable drum, a brake band engageabletherewith, pivoted levers engageable with said braking 1 means formoving the same into engagement with said drum, said levers cooperatingto' provide a stop for said brake band to limit the contraction thereof,and stop means for limiting the circumferential movement of one end ofsaid band when the same is moved into engagement with said drum.

11. In a brake mechanism, a rotatable drum, braking means engageabletherewith, pivoted levers engageable with said braking means for movinthe same into engagement with said drum, ree floating means between saidlevers, and a cam for urging said means outwardly radially of said drumto separate said levers to expand said braking means, said free floatingmeans being guided tangentially by said. levers to equalize anyunbalanced forces between said levers.

12. In a brake mechanism, a rotatable drum, a brake band engageabletherewith, a pair of pivoted levers engageable with said 65 brake band,free floating means between said levers for forcin n. ..n a art toexpand said brake band, sai levers ing formed with cooperating sto meansto limit the contraction of said bra e band, and stop means for limitingthe circumferential movement of one end of said band when said band ismoved into engagement with said drum.

, Signed by me at South Bend, Indiana, this 1st day of May, 1929.

ROBERT F. KOHR.

CERTIIIFRCATIE (0 11 C(DRRECTMDN.

Pitteiit Ne. 11, 99,%7. March 7, i933.

MNBERT 1F. iitiiiiiit.

it is hereby certified that error appears in the printedspeeiiietitiettei time above ttttmbereti patent requiring eeri'eetieiias ieilews: Page 3, beginning with tine 3i strike out :tlli ts antiineitttiing line 5th, comprising eiaims9 and M; same page, times 51 and62, for the elaim mtmerztis "iii and 112" read "9 and it)" respectiveiy;anti that the said Letters Patent should be read with these correctionstherein that the same may eeniemt is the record of the ease in thePatent @iiiee.

Signed and seated this ilitit day of limit, A. D. i933.

M. .i. Meere. (Semi) Acting Getstittissietter 0i Patents.

